The shape of the lesson
By the end of the lesson, learners can
- Security, privacy, integrity: Think of a hospital database of patient records.
- Protect the data and the system: The syllabus asks you to appreciate the need for both.
- Who are you?: Every security measure that limits users depends on first knowing who the user is.
- Security: protecting data from loss, damage and unauthorised access.
- Privacy: who has the right to see and use personal data; protected by law.
- Integrity: data is accurate, complete, consistent and up to date.
- Measures: name the measure, then say how it works and what it protects against.
One picture every idea returns to
Data security means protecting data from loss, damage and unauthorised access. Data privacy is about who has the right to see and use personal data, and is protected by law (data protection legislation). Data integrity means the data is accurate, complete, consistent and up to date. Security measures protect privacy and integrity, but they are not the same thing. A system needs user accounts and authentication (passwords, biometrics, digital signatures) to know who is using it, access rights to limit what each user can do, and encryption so that stolen data cannot be understood.
Forty-five minutes, phase by phase
| Time | Phase | What happens in the room | Grouping |
|---|---|---|---|
| 0 to 5 min | Hook: predict | Open with the question in the title, Three words, three jobs.. Security, privacy and integrity are often used as if they meant the same thing, but examiners treat them as three separate ideas. Put the figure on the board: it is the one picture every idea in the lesson returns to. | Whole class, then pairs |
| 5 to 13 min | Teach and check: Security, privacy, integrity | Think of a hospital database of patient records. Your turn: A bank stores a customer's balance as 1500 when it should be 15 000. Which of the three has been lost? | Whole class, then pairs |
| 13 to 21 min | Teach and check: Protect the data and the system | The syllabus asks you to appreciate the need for both. Model the worked example Data or system? on the board, one line at a time. | Pairs |
| 21 to 30 min | Teach and check: Who are you? | Every security measure that limits users depends on first knowing who the user is. Project tab 6 of the lab (Symmetric and asymmetric encryption) and let a student drive it while the class predicts. Your turn: Explain why a digital signature is encrypted with the sender's private key and not the receiver's public key. | Anticipation / Reaction Guide |
| 30 to 36 min | Check | The four Stage 1 questions from the student lesson, answered on mini whiteboards or by show of fingers. Re-teach the one most get wrong. | Individual, then whole class |
| 36 to 43 min | Plenary | The exam-style questions from Stage 2, one at a time: thirty seconds alone, then a random call. The feedback lines in the key give the examiner's wording. | Individual, random call |
| 43 to 45 min | Exit and homework | Set the worksheet below (6 questions, 19 marks). Learners self-assess against the objectives before they leave. | Individual |
Protect the parts that carry the learning
The sequence carries about fifty minutes of material, so the lab is driven by one student while the class predicts rather than explored freely. Times are a guide.
Protected: the check at 30 minutes. It is the only individual read on whether the key idea landed, and it is not cut.
Cut first if the build overruns: the last check in Who are you?, never the check or the plenary.
In a 60 minute block: run worksheet questions 1 to 3 in class as a Rally Coach set and model both the hardest worked example and its check live.
Anticipation / Reaction Guide
Before the lesson, students mark five statements true or false. After the teaching they mark them again and justify any change of mind in one sentence each. The statements come from the examiner traps below.
The full structure, with its variations and the other twelve, is on the cooperative-learning page.
What to head off, and how
| Trap learners fall into | Teaching move that pre-empts it |
|---|---|
| Do not define one term using another ("privacy means keeping data secure"). | Privacy is about who has the right to see personal data; security is about protecting data; integrity is about data being correct. |
| A backup protects against loss of data. | It does nothing to stop unauthorised access: a stolen backup is a privacy breach unless it is encrypted. |
| Encryption does not prevent hacking or interception. | Write that it makes intercepted data unintelligible (meaningless) to anyone without the key. |
Security, privacy and integrity of data: worksheet
6 questions, 19 marks. Written in the style of the papers; no past paper question is reproduced.
Explain the difference between the terms security, privacy and integrity of data.
A medical centre keeps patient records on a networked server. Describe two measures that protect the data and two measures that protect the computer system.
A company replaces passwords with fingerprint scanners. Give one advantage and two disadvantages of this change.
Describe how a digital signature is created by the sender and checked by the receiver.
A student writes: "Encryption keeps data private because it stops hackers getting the data." Explain why this statement is not accurate.
In a school system, teachers, students and office staff all use the same student records database. Describe how access rights could be set up to protect the data.
Answer key and marking notes
- Security: protecting data from loss, corruption or unauthorised access (and being able to recover it).
- Privacy: the right of individuals to control who can access and use their personal data; data used only for the purpose it was collected for.
- Integrity: the data is accurate, complete, consistent and up to date.
- Data: regular backups stored off site, so records can be restored after loss or corruption.
- Data: encryption of the records, so stolen data cannot be understood (or access rights limiting who can read or edit records).
- System: a firewall that checks incoming and outgoing traffic against rules and blocks unauthorised traffic.
- System: anti-virus / anti-malware software kept up to date, or user accounts with strong passwords (any valid measure, described).
- Advantage: a fingerprint cannot be forgotten, guessed or written down and shared.
- Disadvantage: false rejections, for example if a finger is cut, dirty or wet.
- Disadvantage: privacy concerns about storing biometric data, and a stolen fingerprint template cannot be changed like a password (or cost of the hardware).
- The sender produces a hash (message digest) of the message.
- The sender encrypts the hash with the sender's private key; this is the digital signature, sent with the message.
- The receiver decrypts the signature with the sender's public key to recover the hash.
- The receiver hashes the received message and compares the two hashes; if they match, the sender is authenticated and the message has not been altered.
- Encryption does not stop data being accessed, intercepted or stolen.
- It makes the data unintelligible / meaningless to anyone who does not have the decryption key.
- Each user logs in with their own account, which belongs to a group (teachers, students, office).
- Office staff: read/write access to contact and admin details; teachers: read/write to marks for their own classes, read-only elsewhere.
- Students: read-only access to their own record only, or no access to other students' records; this protects privacy and integrity.
6 multiple-choice questions on this lesson
From the topic question bank. Assign them in the app for a marked score in your gradebook, or run the topic as a class game.
Which statement correctly describes data integrity?
- AThe data is accurate, complete, consistent and up to date
- BThe data is protected from loss, damage and unauthorised access
- COnly people with the right to see personal data are able to use it
- DThe data is encrypted so that it cannot be understood if it is stolen
A hospital receptionist, who is allowed to use the patient database to book appointments, looks up a famous patient's diagnosis out of curiosity. Which has been breached?
- AData privacy
- BData integrity
- CData security against loss
- DData validation
How is a digital signature created by the sender?
- AA hash (digest) of the message is encrypted with the sender's private key
- BA hash (digest) of the message is encrypted with the sender's public key
- CThe whole message is encrypted with the receiver's private key
- DThe sender's password is attached to the message and encrypted with the receiver's public key
A school backs up its student records to a portable disk every night. The disk is stolen from a teacher's car. Which statement is correct?
- AUnless the backup was encrypted, the thief can read the records, so privacy is breached even though no data is lost
- BThe data is safe because a backup protects against all forms of unauthorised access
- CIntegrity has been lost because the records on the school's server are now inaccurate
- DNothing has been breached because the original records are still on the school's server
A company replaces passwords with fingerprint scanners to log in. Which is a genuine disadvantage of this change?
- AIf the stored fingerprint templates are stolen, a user cannot change their fingerprint as they could change a password
- BUsers are likely to forget their fingerprint, so many accounts will be locked out
- CFingerprints can easily be told to a colleague, so accounts will be shared
- DA fingerprint scanner can only be used by one user, so each person needs their own scanner
A student writes: "Encryption keeps data private because it stops hackers getting the data." Which correction is most accurate?
- AEncryption does not stop data being intercepted or stolen; it makes the data unintelligible to anyone without the key
- BEncryption stops hackers getting the data, but only if a firewall is also installed
- CEncryption protects data integrity, not privacy, so it has nothing to do with hackers
- DEncryption only works on data stored on a disk, so it cannot protect data sent over a network
Quiz key
Integrity means data is accurate, complete, consistent and up to date. Protecting data from loss, damage and unauthorised access is data security. Controlling who has the right to see personal data is data privacy. Encryption is one security measure, not a definition of integrity.
Using personal data for a purpose it was not collected for breaks the patient's privacy. The data has not been changed, so integrity is intact. Nothing has been lost or damaged. Validation checks data as it is entered and is not involved here.
Only the sender holds the sender's private key, so a digest encrypted with it proves who sent the message; the receiver checks it with the sender's public key. Anyone has the public key, so it proves nothing about the sender. Nobody but the receiver holds the receiver's private key. Sending a password would reveal it and does not prove the message is unchanged.
A backup protects against loss, not against unauthorised access; an unencrypted stolen copy exposes personal data. Backups do not stop anyone reading them. The server copy is unchanged, so its integrity is fine. The original still existing does not stop the privacy breach.
A biometric is permanent: a stolen template cannot be replaced, unlike a password (false rejections are another drawback). Biometrics cannot be forgotten or easily shared, which are their advantages over passwords. One scanner can store templates for many users.
Encrypted data can still be intercepted or copied; the point is that it is meaningless without the key, which protects privacy. A firewall is a separate measure and does not change what encryption does. Encryption mainly protects confidentiality, so it is linked to privacy. It is widely used on data in transmission, such as https.
What to project
The student lesson embeds these tabs. Open them full screen on the projector; every slider has a drag handle on the stage.
Slides for this lesson
A projectable deck for every pack is on the way. Until then, present the student lesson full screen: its sections, figure and lab tabs follow the same order as the plan above.